The parking aid PDC supports the driver on manouvering into and out of parking spaces: signal tones and a visible indicator indicate the current distance to an obstacle. The signal functions of the PDC are:
The shorter the distance to the obstruction, the faster the sequence of the individual tones. A distance below approx. 25 cm is signalled by a continuous sound.
If the vehicle is moved along the side of a wall, the continuous tone of the distance warning is deactivated to avoid distracting the driver. If the vehicle continues to approach the wall, the distance warning is reactivated.
Important: responsibility on the part of the driver
PDC is unable to replace the personal assessment of obstacles. Sensors have a blind spot. In this blind spot, it is no longer possible to detect objects. The detection of obstacles can reach the limits of physical ultrasonic measurement, e.g. in the case of trailer towbars and trailer hitches or thin and painted objects. Low obstacles that have already been indicated can ”disappear” again before a continuous tone is sounded (e.g. a high edge of the kerb).
For this reason, the assessment of obstacles, even with PDC, is the responsibility of the driver.
The park distance control can be switched on and off manually with the PDC button.
The PDC button is fitted to the left of the start/stop button. The PDC button consists of
The indicator lamp in the PDC button indicates
The distance between the vehicle and the obstacle is measured by ultrasonic converters in the bumpers.
The distance between the vehicle and an obstruction is monitored in accordance with the sonar principle. The ultrasonic converters emit an ultrasonic signal. This ultrasonic signal is reflected by obstacles. The ultrasonic converters receive these echoes, amplify them and convert them into a digital signal. The digital signals are sent across the data line to the PDC control unit.
The control unit compares the data of the individual ultrasonic converters and calculates the shortest distance between the ultrasonic converters and obstacle.
The measuring range of the ultrasonic converters lies between approx. 20 cm and a maximum of approx. 150 cm. If the minimum detectable distance increases beyond the permissible extent, a fault code is stored in the fault code memory. Soiling, moisture, ice and snow can lead to an increase in the minimum detectable distance beyond the permitted level.
Each ultrasonic converter has its own electronic component, its own voltage supply and its own data link to the PDC control unit.
Four ultrasonic converters are fitted in the front bumper
The rear ultrasonic converters function in the same way as the front ultrasonic converters.
Four ultrasonic converters are fitted in the rear bumper
If the PDC control unit detects that a trailer has been hitched and electrically connected, the rear ultrasonic converters are deactivated.
The PDC control unit is located in the rear of the luggage compartment on the right.
The PDC control unit receives the information on the switch-on/off conditions of the system via the K-CAN bus system:
The PDC control unit
Various other control units in the composite system are involved in the distance warning function:
The PDC control unit only provides the distance indications between the ultrasonic converters and the obstacle. From this, the ASK calculates the tone sequence of the acoustic distance warning.
The acoustic distance warning overrides the audio sound.
The distance warning for reversing is output via the rear loudspeakers.
The rear loudspeakers are activated by the Audio System Controller (ASK). Signal path: PDC control unit -> K-CAN bus system -> Control Display -> Audio System Controller ASK -> DSP amplifier - > rear loudspeakers.
The front distance warning is output, depending on the coding, via
If faults have occurred, a warning tone is also issued.
The distance to an obstacle can also be displayed visually in the Control Display. If an obstacle is further away, it is displayed in the Control Display before a sound signal is issued (green display).
Displaying the distance: in the Control Display, select ”Configuration”. Press ”PDC image”. The PDC indicator appears as soon as the PDC is switched on automatically or manually. The PDC indicator overrides other displays. When the PDC system is switched off again, the previous display appears automatically in the Control Display.
The PDC parking aid is switched on when the driver
The PDC parking aid is switched off
Circumstances representing problems for the switch-on/off conditions
In borderline situations, the PDC system can signal the presence of obstacles although none are in fact present. Or obstacles that are present are not detected:
Problem case: The PDC system signals the presence of an obstacle where there is none:
In the following situations, it is possible that the ultrasonic converters signal a non-existent obstruction:
Problem case: The PDC system does not detect the presence of an obstacle:
In the following situations, it is possible that the ultrasonic converters do not detect an obstruction:
When there is currently a fault in the PDC system,
The system can not be switched on.
Important: Prior to troubleshooting, first check the mechanical condition of the ultrasonic converters:
Particular care must be taken before starting extensive troubleshooting to ensure that the converters are fitted correctly in their retaining fixtures and are free of dirt.
Important: avoid new influencing variables during troubleshooting:
During troubleshooting there should be no obstruction closer than 40 cm to the converter. An obstacle in the immediate proximity of the ultrasonic converters changes the characteristics of the PDC system.
Keep the ultrasonic converters clean and free of ice to ensure their full operational capability.
Do not direct high-pressure cleaners directly at the ultrasonic converters. Always keep a distance of at least 10 cm.
An acoustic signal is output via the gong for as long as reverse gear is engaged. The reversing gong is switched off immediately if the PDC detects an obstruction within its measuring range and issues a distance warning.